Tube rolling - 12AU7 to 6922 adapter


I thought I’d transfer this thread over to this discussion category from tech talk. I recently changed preamps - from 12AU7 circuitry to 6922. Yet, over the years, I’ve accumulated a sizable stash of NOS 12AU7’s - some of which I really enjoy.

At @kdude66’s suggestion, I purchased these 12AU7 to 6922 adapters. My main concern was damaging my pricey new preamp. No problem. It’s sounding kind of great! These adapters are built very well using real ceramic sockets. They fit snugly in the 6922 sockets. For those using components with 6922 tubes, this opens up a whole new world of 12AU7 tube-rolling possibilities. The only drawback is that they add about 7/8" height. So, I need to build a riser to raise the preamp lid. It should be simple.
steakster

Showing 1 response by gs5556

yogi: all that does is jump pins 4 & 5 and connects pin 9 to ground to put 6.3 volts in parallel to the 12AU7. The tube can run at either 6 or 12 volts.

op: There should not be an issue running a lower gain tube, however the circuit is optimized for the 6922 and the 12AU7 may be operating outside its sweet spot. Try listening to a 6922 to see if there is a difference.